Multiplying mechanism



7 Sheets-Sheet 1 Filed Sept. 2'7, 1946 now mom N NE INVEN TOR. HAROLD P M X ER BY 4 ,dzhc

ATTO R N EY May 8, 1951 H. P. MIXER MULTIPLYING MECHANISM '7 Sheets-Sheet 5 Filed Sept. 27, 1946 0000000 0900000 OOOOOOO INVENTOR. HAROLD P MIXER BY J2; .L in? ATTO R N EY May 8, 1951 H. P. MIXER MULTIPLYING MECHANISM 7 Sheets-Sheet 4 Filed Sept. 27, 1946 INVENTOR HAROLD P. MIXER BY y. Liz 4.;

ATTORNEY y 8, 1951 H. P. MIXER 2,552,201

MULTIPLYING MECHANISM Filed Sept. 27, 1946 7 Shets-Sheet 5 INVENTOR. HAROLD P. MIXER BY JQLLAZIJ-LF ATTO R N EY May 8, 1951 H. P. MIXER ,201

MULTIPLYING MECHANISM I Filed Sept. 27, 1946 7 Sheets-Sheet 6 SUB. CLOCKWlSE o 20' #0 so era an 20' I410 no a zoozza' mo zw'gm'aov' 320294 0 RESTORING I BAR I37 CAM 23o i ACC. MESH r CAM 245 5 ouT RESTORE 1 ///A- TOTAL RAcKs CAM 262 RESTORING BAR 308 CAM 33o A DD COUNTER 'CLOC KW ISE FIG 13 INVEN TOR HAROLD R MIXER ATTORN EY y 8, 1951 H. P. MIXER 2,552,201

MULTIPLYING MECHANISM Filed Sept. 2'7, 1946 7 Sheets-Sheet '7 INVENTOR HAROLD R MIXER ATTOR N EY Patented May 8, 1951 MULTIPLYING MECHANISM Harold I. Mixer, 'Rockville Centre, N. Y., assignor to Remington Rand Inc., New York, N. Y., a corporation of Delaware Application September 27, 1946, Serial No. 699,145

Claims. 1

My invention relates to computing machines and more particularly to such machines whose operations involve the obtaining and the accumulation, additively or s-ubtractively, of products; and it has for its principal object to provide improved multiplying mechanism for such machines. The invention relates to that class of computing machines that yield a product by true multiplying mechanism as distinguished from that class of machine whose mechanism is essentially that of an adding machine and in which when a number multiplied by 8, for example, the number is set up and the machine operated 3 times.

The invention has for one of its objects to provide mechanism which yields partial products, that is, the product of a multiplicand by a digit of a multiplier and which transfers said partial product in its entirety-to an accumulator by one continuous movement or at least substantially so. The several partial products constituting the whole product of a multiplicand by a plural digit multiplier'may be accumulated additively or may be subtracted from a previously accumulated amount as, for example, in the figuring of discounts.

The invention has for further objects to make certain subsidiary improvements in the mechanism.

The invention includes a multiplying logarithmic spiral pair laid off to-yield the products of the nine digits by one another covering the range of one to eighty-0ne and mechanism for controlling the operation of such a pair and for entering the products into an accumulator. According to the invention a series of these pairs and their associate mechanism is provided, one for each denomination or order, and gearing for conveying the movement of each logarithmic pair to a wheel of an accumulator so that as the several pairs are rotated each to yield the product of two digits, the whole product is rolled at once into said accumulator. I am not aware of any prior construction of which this is true. The invention also includes means to add one unit of movement at each operation of a logarithmic pair to compensate for the fact that the operation of such pairs starts at one instead of at zero. Preferably, this additional one is added on the acciunulator as a portion or extension of the continuous movement of the logarithmic pair.

To the above and other ends the invention consists of certain features of construction and combinations and arrangements of parts, all of 2 which will be fully described herein and particularly pointed out in the claims.

An instance of the invention is illustratedin the accompanying drawings, in which:

Fig. 1 is a longitudinal vertical section of a machine having the invention embodied-therein;

Fig. 2 is a front elevation of the machine;

Fig. 3 is an enlarged, fragmentary view, partly insection, showing certain differential racks and their associate devices;

Fig. 4 is a detail in sectionon the line 4-.4.of Fig. 1 and looking in the directionof the arrow;

Fig, 5 is a plan View of the machine;

Fig. 6 is a fragmentary enlarged plan view of certain parts employed in total taking;

Figs. '7, 8 and 9 are fragmentary elevations of the key boards and their cooperating mechanism, the parts being shown in'the act of multiplying 1 by 9;

Fig. '7 is a view looking leftward from the line 'l'! of Fig. 8;

Fig.8 is a front elevation;

Fig. 9 is a view with some parts in section on the line 9S= of Fig. 8 and looking toward the left;

Fig, 10 is a diagram of a'spiral pair;

Fig. 11 shows a a-pair of spiral gears together with scales illustrating the different numerical positionsof said gears;

Fig. 12'is a time-chart;

Figs. 13-16, inc., are detached views of operating cams and the levers more immediately operated thereby;

Fig. 17 is a cross section through the accumulator;

Fig. 1-8 is a cross section taken along line |BH3 of Fig. 1'7; and

Figs. 19, 20, and 21 show the zeroizing mechanism for the accumulator.

The main frame of the machine shown in the drawings, comprises a base plate '58 (Figs. 1 and 2), a right hand side plate 5!, a left hand side plate 52, and certain cross members joining said side plates.

Themultiplying elements consist of like pairs of spirals N and L rolling. the one spiral on the other, one pair for each denomination of the .multiplicand. The numeral spirals N are journaledon a cross shaft It! and the logarithm spirals (herein for brevity called the log spirals) on a cross shaft I02. A pair of these spirals is shown diagrammatically in Fig. 10, and in their physical forms in Fig. 11. When the gear L is displaced from its initial position in accordance with a logarithm, the gear N is displaced in accordance with the antilog of that logarithm. When the gear L is displaced in accordance with the sum of the logarithms of two digits, the gear N is displaced in accordance with the product of those digits.

In Fig. the spirals are shown in their initial position, spiral N being at 1 and L at 0, which is log 1. In Fig. 11, the spirals are shown retracted to a certain Zero position which will be explained hereinafter. By turning them one step from their Fig. 11 positions, spiral N counterclockwise and spiral L clockwise, they will be brought to initial logarithmic position where an index Hi l on spiral N registers with graduation l on a schematically drawn scale )5, and an index H36 on spiral L registers with graduation 1 on a similar logarithmic scale ml. In other words, this movement will bring the spiral to the position shown diagrammatically in Fig. 10. The following discussion will be based on this initial position, the zero position of Fig. 11 being ignored for the present. The indexes and scales are drawn in Fig. 11 for explanatory purposes only. The graduations on the scale I05 are at equal intervals, representing numbers, and those of scale it)? are at unequal intervals appropriate to the respective logarithms of such numbers. If we take the angular interval between two of the graduations of scale we as our unit of angular measurement then we may say that to bring i spiral N to represent a number x, we turn it from its initial 1 position through an angle equal to r1. In such turning, spiral L will turn through an angle y proportional to, but not equal to, log at. We may say, therefore, that it i the law of this spiral pair that where a is a constant.

Spiral pairs of the general type, represented by the equation, are known in calculating machines, and they are capable of performing multiplication and division. For example, such a pair is described in the patent to T. W. Ross, No.

1,503,810, issued August 5, 1924. In that patent the two spirals are connected to roll together by two reverse tapes; but in the present instance I have preferred to make them as queer gears having teeth 553, the spiral curves being at the pitch lines. Multiplication and division may be performed with such spirals. If spiral L be turned through an angle equal to alog 8, index We will move to 8 on its scale. If now, spiral L be turned through a further angle equal to clog 3, index its will point to 24 on its scale. Or, if spiral L be set at alog 48, and then turned counter-clockwise through an angle clog 1.6, index iiii will come to 3, the quotient of 48 divided by 16. In the said Ross patent, however, the spirals are graduated only from 1 to 19, lower orders of the product being obtained by interpolation, as with a slide rule. According to the present invention the spirals are laid off from 1 to 81, so that, within that range the rotations of a spiral N are directly proportional to the products, less 1.

In Fig. 10, C is the distance between the centers of shafts NH and H12, R is any radiant of spiral N, and r the corresponding radiant of spiral L. In any position of the spirals, the momentary rate of increase of angle y with respect toangle :0, is obviously equal to iii Also, said rate of increase is equal to Differentiating Equation 1, therefore.

R d 1/ (2) 7 da: a x

where M is the modulus of logarithms to the base 10 (.4343).

According to these equations, R and r are each proportional to C. Varying the latter will, therefore, change the size of the curves, but not their shape. But R and 1' do not bear this simple relation to a, and varying the latter will, therefore, change the shapes of the curves. Obviously, a may be said to be equal to the ratio of the unit of measurement of the angular movement of spiral L to that of spiral N, and therefore, to increase a is to increase the total angle through which the spiral L swings. A little consideration of Equation 4 will show that to increase a will make comparatively little difference in the radiants when :c=l, but will appreciably increase R, where m=81. Also, changing the unit of angle would change proportionately the number of degrees of angle covered by the scales I05 and H31, and the angles through which the spirals turn. Thus, within the purview of the above equations, a number of spiral pairs may be worked out difiering more or less from one another, and the choice of one of them as the most desirable will probably be based on mechanical considerations which may be better understood after describing the balance of the mechanism.

The spirals chosen for illustration and shown in the drawings, were arrived at in some such way as follows: The distance C was put at 2.5 inches. The spirals were designed to yield the thirty-six diiferent products obtained by multiplying the digits l-9, such products ranging from 1 to 81. It seemed desirable for the numeral spiral to have a maximum movement of about three quarters of a turn, and 3 was therefore chosen as the unit of angular movement. It seemed suitable for the log spiral to have a maximum swing of somewhat more than a half turn, and the several logarithmic radiants r were therefore laid off each at an angle of multiplied by log :0, so that log 81 is represented by an angle of 190.8, log 2 by an angle of 30.1, and so on. The factor it therefore became 100 divided by 3%:30. Equations 4 and 5 thus became:

, 30M (6) x+30M and If we fix C at 2.5 inches, and remember that M =xi3 l3, the values of R and 'r in inches reduce to 5 and Some change in the cooperating mechanism might make it desirable to change the proportions of the spirals. A pair in which the unit of angle is increased to 4 and log a: is multiplied by 160, may, perhaps, be preferable to the one shown in the drawings. In this instance, (1:40. The spirals may be varied in other ways.

In each denomination, the spiral pair L, N is included in a train of gearing shown in Figs. 1, 2, 5 and 9. The numeral spiral N, is part of a rigid structure including also a gear wheel H and a spacer III, the three parts being secured together by rivets H2 and the whole journaled on the shaft IOI. Between the gears N and H0, in the space provided by the spacer III, is a gear II3 journaled on the shaft I02 beside the spiral gear L, to which it is secured into one rigid structure, by rivets II4. Means to actuate this gear II3 and, through it, the entire train, will be described presently.

According to the invention the partial products obtained by these several multiplying gear trains, are added on an accumulator. To this end, the gear IIO drives a pinion II5 which is fast to a larger gear H5, said gears being journaled on a cross shaft Ill. An accumulator I20 has its wheels I2I and pinions I22 journaled on a shaft I23 supported by arms I24 fast to a shaft I25, the rocking of which moves the pinions I22 into and out of mesh with the gears IIB in the manner familiar in adding machines. The gearing is preferably s0 proportioned that turning the gear IIO through a unit angle (B in the specific instance illustrated) turns gear I I6 to the extent of l tooth.

Means are provided whereby, when the gearing is operated to register a product, the gear I It has added to its motion an additional movement equal to one angular unit, in order to compensate for the fact that, when the numeral spiral N is in its initial position, it already stands at 1. To this end, as illustrated and preferably, when after a setting, the parts are restored to normal position, the wheel III) and the spiral N are not stopped at the initial logarithmic position shown in Fig. 10, but are retracted to the normal zero position shown in Figs. 11 and l, where the spiral N and wheel I I0 stand retracted one angular unit beyond said initial position. The means to this end may be Varied in detail. As shown, the member L is provided with an extra tooth I2? (Fig. 11) cooperating with a notch I28 in the end of the member N in such wise that when the gear II3 and member L are turned counter-clockwise a measured distance beyond their logarithmic starting point, the member N is retracted through one unit angle. The tooth I2! and notch I28 are not parts of the spiral gearing, but constitute an additional bit of ordinary spur gearing, entirely independent of the logarithmic spirals. In Fig. 11, the pitch lines I 29 and I30 of the gears L and N, respectively, are drawn in, and it will be noted that they are spirals down to the last logarithmic teeth, and concentric fro-m there on. In fact, it will be observed in Fig. 11 that when the parts are in the normal position in question, the teeth I03 of the logarithmic series, have moved out of mesh with one another; but the two parts L and N are still geared together, and when they are turned to set up a number, the logarithmic 6 teeth will roll into mesh properly. The additional movement of the spiral L and gear II3 to accomplish this normal positioning of the parts, is not alogarithmic movement but is an empirical one amounting, the tooth I21 and notch I28 being what they are, to whatever movement is necessary to turn the spiral N back one unit angle. Thus, when, starting at normal position, we set up the number m, these parts will be turned through an angle equal to the said empirical angle plus alog m; and the spiral N and the gear III) will be turned through an angle m. Whether the accumulator I be thrown into mesh with its actuator H0 on the advance or on the return stroke, the pinion I23 will be turned m teeth in one direction or the other.

The mean to control and to actuate the above described trains to multiply numbers, in other words, in the illustrated instance, to actuate and control the gear II3, may be varied considerably. An improved means to actuate said gear II3, is shown in the drawings. Said gear is in constant mesh with a rack bar I slidably mounted on upper cross frame bars I3I and lower bars I32, passing through slots H9 in said rack bar. Springs I urge said rack bars toward the front of the machine for their advance strokes. Each of these frames actuates the whole train of gearing H9, II3, L, N, H0, II3, and may obviously act primarily on any member of said train. As illustrated, they are attached to a cross bar I36 and act to draw the racks I30 toward the front of the machine. They are retracted to normal position by a restoring bar I3'I playing in a slot I33 in each of said rack bars and reciprocated from a drive shaft I40 in the base of the machine, as will be described hereinafter. A multiplicand slide bar Idi is mounted on the upper guide bars I3I beside the rack bar I30, and a multiplier slide bar I62 is similarly mounted on the lower guide bars I32. Clips I33 sprung into shallow slots in the bars I3I and I32, guide the rack bars I30 and MI on cross bars I3I and I30 and I42 on bars I32 (Fig. 3). The bar I II has rack teeth on its lower edge and the bar I42 on its upper edge, the two racks meshing with a pinion I53 journaled on a stud I 55 riveted to the bar I30. The Whole amounts to differential gearing such that if either bar id! or I42 slides leftward in Fig. 1, the bar I 30 will slide in the same direction through one-half the distance; and if both bars MI and H22 be set differential distances leftward of normal, the bar I30 will be advanced a distance equal to one-half of the sum of the distances advanced by the two bars MI and I42, as shown in Fig. 9. In operation, the gear II3 is advanced (turned clockwise) through measured differential angle appropriate to the logarithms of the several products ranging from 1 to 81, and the bar I30 is advanced the same linear distances as measured on the pitch line of said gear; and, obviously, such logarithmic distances as applied to the bars I II and I42 are measured on a-scale twice that applied to bar I30.

As far as the mechanism above described is concerned, any suitable means may be employed to control the differential settings of the bars MI and IE2. In the present instance they are con-- trolled respectively by a set of multiplicand keys I50, and a row of nine multiplier keys I5I. For simplicity, the key-boards are shown in more or less conventional form. The accumulator I20 may have a step-by-step travel rightward after multiplying by each digit of the multiplier, as is common in calculating machines; but I have preferred instead to provide a full set of multiplying trains, one for each denomination of the product, and to make the multiplicand key-board travel across them. In order to illustrate the invention as simply as possible, I have shown only eight places in the multiplying mechanism, and four rows of multiplicand keys I50.

The multiplicand keys IEEI are mounted in a carriage comprising a top plate I53, a bottom plate I 2, a front plate I55 and a rear plate I56, the whole slidable on cross frame bars or rods I51 and I58. The key stems lfiu are slidably mounted in slots in the plates I53 and its, being fanned in as shown to bring their lower ends to distances apart, proportional to the logarithms of the digits, said lower ends, when the keys are depressed, serving as stops for the bars MI. The keys have restoring springs IGI, and each of them has a lug I62 projecting through a conventional toothed locking slide I63 (Fig. 7) mounted in the plates I55 and I56, and each urged frontward by a spring-pressed pin I65. When any key is depressed it will be locked down by a tooth of the slide I83, and will be released when another key is depressed in the same row, in the'manner well known; or all of the keys may be released by pushing in the forwardly projecting ends of the slides I63.

In order to retain the main rack bar I31] in its normal zero position unless one of the keys Ital controlling its denomination at the moment, is depressed, the following means are provided. The front end of said rack I36 is made a little lower than the end of the bar MI, and a stop bar or look I63, slidably mounted in the plates I53 and I54, stands normally in the path of the rack bar I39, being urged downward by a spring pressed pin I65 bearing on an ear of said stop bar. A slide bar I68, mounted beside the locking bar I63 and standing in front of it as viewed in Fig. 1, has windows into which project the lugs I62 on the key stems, but the lower right hand slope of each such window is continued into an incline I'Ill, so that, when a key is depressed the bar I58 is moved and retained rearward (Fig. 7) The slide I66 has at its upper rear corner a cutout I59 to prevent said slide from being affected by the spring pressed pin ltd. The stop bar I66 has a lug I5'I projecting into a window of said slide I68 and cooperating with an incline H2, so that when a key is depressed said locking slide IE6 is pulled upward and no longer obstructs the motion of the rack bar I38. If, for example, the multiplicand was 361, depression of the 3 and the 7 keys would free the racks I30 in the hundreds and units places, as far as the multiplicand is concerned, but those in the thousands and tens places would remain locked in normal position.

The key-board carriage may be fed leftward by any suitable means, but, for simplicity, no such means is shown herein, the carriage being moved by hand. In order to locate the carriage in any of its four positions, any suitable latch may be provided, such as a pivoted thumb-operated member I59 (Figs. 8 and 9) pivoted to an ear of the front plate I55 and spring pressed into one of the notches I$9 in the bar I51. The key-board carriage is moved at a time when all of the differential bars I30, MI and H32, are held in their extreme retracted positions by the restoring bar I31.

Means are provided to hold inactive all multiplying trains except whatever four of them are at the time under control of the multiplicand key-board. This may be done in a variety of ways. As shown (Figs. 1, 4 and 5), a seriesof pawls I89, one for each train, are pivoted on a cross shaft IBI, and urged each by a spring I83 into locking engagement with the large gear III! of its associate train. The heels of said pawls project forwardly, and, as the carriage is moved back or forth, a flange I84 on the rear edge of its upper frame plate moves over them and, by its inclined ends, cams said heels downward and releases the four pawls immediately behind said carriage. The pawls not so released prevent their associated multiplying trains from operating.

The multiplier key-board consists of the row of multiplier keys I5I and their appurtenances. The stems IQI of said keys are guided in upper and lower guide brackets I92 and I93, respectively, said brackets being secured to the right hand'frame piece 5I of the machine. The several key stems have lugs I94 projecting therefrom through the usual toothed windows of a conventional locking slide I95, like the slides I63 of the multiplicand key-board. Said stems are provided with any suitable restoring springs. When any key IEI is depressed it is locked down by the slide I95 and releases any previously depressd key. The lower end of each key stem 5%, stands above a stud I91, projecting from the horizontal arm of a bell-crank I98, which is an element of the multiplier stop basket now to be described.

Two transverse frame rods 2% and 2% I, support right and left hand guide bars or brackets 202 and 2%, respectively. These are sheet metal bars each having two sleeves or hub-like collars 2M- secured thereto, and the frame bars 205i and 2%! pass through these sleeves, which are then secured in place by set screws. The bars 262 and 263 constitute guide combs for nine stop bars 2%. Each stop bar is supported at its right hand end by one of the ball-cranks I98, and at its left hand end by a link 206. Said bell-cranks are pivoted on a rod 2%? supported at its ends by brackets or ears 298 formed off from the ends of the bar 262; and the links 2% are similarly pivoted on a rod 2H) carried by cars 2H formed off" from the ends of the bar 2&3. Each stop bar 2&5 has in its upper edge a series of stop teeth 2I2 separated by notches, one notch normally standing in line with the end of each of the multiplier rack bars I 32. The construction is such that, when the machine is operated, a rack I42 may advance through the notches in unoperated bars 205, and it will be arrested by a tooth of whichever of said bars 265 has been displaced by the depression of its associated key I5I, which depression shifts the stop bar slightly to the right, bringing one of its teeth 2I2 into the path of each of the racks Hi2. Thus, all of the racks I 32 that advance in any one operation, advance to the same extent, appropriate to the logarithm of the multiplier digit. The stop bars 265 have the same logarithmic spacing from one another as the key stops Ififi of the multiplicand key-board. It will be perceived that in a multiplying opera-- tion, in each denomination, the rack I l! will advance a distance appropriate to the log of the multiplicand digit set up in that denomination, the rack Id? will advance a distance appropriate to the log of the multiplier digit, and the rack I30 will advance and operate the multiplying train to an extent appropriate to the sum of the two logarithms, that is, to the logarithm of the product of the two digits.

' In order to lock all of the main rack bars I30 in normal position unless a multiplier key has 9 been depressed, the following means are provided. Behind all of the stop bars 205, there is similarly mounted another stop bar 215 having teeth 219 normally retaining all four of the active rack bars I30 in their zero positions, this bar bein i in addition to the individual stops 166 of the multiplicand key-board; and this stop bar 215 is moved to release position by the depression of any one of the nine multiplier keys 151. It is like the stop bars 2135 except that its upper notched edge stands higher than theirs as shown in the drawings. The lower front corner of the rack bar 130 is higher than that of the multiplier rack 142, so that whereas a tooth of the bar 215 may arrest rack 130, said rack, when it advances frontward, can pass over the top of a tooth of a. bar 2115 (Figs. 8 and 9).

The locking bar 215 is controlled by the keys 151 by means best shown in Figs. 8 and 9. The lugs 194 on the key stems 191, project through windows in a slide 228, each such window having an inclined edge 221 such that when the key is depressed the slide is forced rearward. Said slide has another window whose upper forward edge 222 is so inclined that, when the slide moves rearward, 2. lug 223 on a push bar 224 is forced downward. Said push bar at its lower end presses down a stud 225 on a bellcrank 226 to the upstanding arm of which the bar 2I5 is pivoted. Said bar 215 is mounted at its other end on a link like the links 296. In short, the bar 215 is mounted and operated in the same way as the bars 265. It differs from them in that its upper edge is higher and in that, instead of a notch, a tooth stands normally in the path of each rack 138; and when bar 215 is operated, the notches thereof come in front of said rack bars and free them to advance.

The mode of operation of the racks I39, I41 and I 42, is as follows. When a. rack 132 is re stored to normal position by the bar 131, the rearward movement of the rack MI is limited by the end of one of its guide slots reaching the cross bar 131; and also, the rack 142 limits in the same way on the bar I32. Each of the three racks is thus at the limit of its rearward movement, and as long as rack I30 is retained either by its upper lock IE or its lower lock. 215, neither of the racks 141 or hi2, can advance, because the two racks are connected together by the pinion M3, and said pinion being held against forward movement, neither rack could advance without moving the other rearward. If the 1 key 159 and the 1 key I51 be depressed (1 times 1) and the machine operated, the rack 130 must advance the distance required to move the spirals L and N from their normal zero positions to their initial logarithmic positions, as above described; and this will entail a forward motion of one or the other of the racks 1 3i, 142, or of both of them, the movement of one of said racks, or the sum of the movements of both of them, amounting of course, to double the distance moved by the rack 131.1. In the design illustrated in the drawing, this is accomplished by making the racks I 31 and 142 of such lengths that, in the normal position shown in Fig. 1, the rack I42 stands in its 1 position and the rack 141 at a distance from the 1 stop 11512 equal to the said double distance. When multiplying 1 by 1, therefore, the rack M2 is held in its normal position by the 1 stop 225 and the rack i 31 advances twice as far as the rack 1 In the drawing, the stop or look. IE5 is shown spaced from the 1 stop Ifiil at this double distance, so that normall the upper front cor- 10 ners of the racks I30 and I 4I are in alignment and lock I66 locks the rack Hi1 also; but this particular disposition of said lock 166 is of no significance, and its purpose is achieved by looking rack 13!! alone.

Fig. 9 shows the parts at the end of the forward stroke when multiplying a multiplicand 1 by a multiplier 19. The 1 multiplicand key I59 has been depressed to move its stem I86 into the path of the rack 141 and to raise the lock 15% out of the path of the rack I311. The 9 multiplier key 1 51 has been depressed to shift its stop bar 2&5 to arresting position and to shift the locking car 215 out of position to restrain the rack 139. The bar I ll has advanced from its normal zero position to its 1 position, thus adding 1, and the rack 1:12 has advanced from its 1 position to its 9 position, thus adding 8 ((12-1). The gearing stands in its 9 posit-ion, and 9 has been added on the accumulator. The rack I30 has advanced beneath and beyond the end of the set 1 key stem of the multiplicand key-board.

The restoring bar I31 for the main rack bars 13E), is reciprocated by two cams 23B, mounted on the cam shaft 14s, one at each side of the machine (Figs. 1, 2 and 14). Each cam acts on a follower roller 231 on a lever 232, pivoted at 233 and connected by a pull link 234 with a lover or arm 235 which is connected with said restoring bar by a push link 236. The arms 235 may be pivoted on or fast to a cross shaft 231. The timing of this train of restoring mechanism will be described hereinafter, in connection with that of other devices.

The accumulator 1211 is thrown into and out of gear with its actuators I 16, by the following means (Figs. 1, 2, 5 and 15). As hereinbefore mentioned, it is supported on arms 124 fast on a rock shaft 125. This shaft is rocked by an arm 22% fast thereon and projecting rearward, a vertical link 24!, a lever 242 pivoted at 243 and carrying a follower roller 244, resting on a cam 245 on the cam shaft M0. The roller is pressed against the cam by a spring 246, the tendency of which is to move the accumulator into mesh with the the wheels 116. The timing will be explained hereinafter.

Applioants multiplying mechanism achieves by far its best results if the accumulator is of a type which is capable of continuous operation without any pause for the purpose of effecting the tens carry, such, for example, as an accumulator of the crawl carry type, and the one partially illustrated in the drawings is, with a slight exception, substantially the same as that described in the patent to C. Gardner, No. 1,828,180, dated October 20, 1931. As shown in Figs. 17 and 18, in each order there is a drive member consisting of a nine-toothed drive pinion 122 having fast thereto a disk 4m] with nine teeth 48! projecting leftward therefrom. In Fig. 18 the disk has been sectioned away and the teeth 491 are shown in section. The drive member 122, dill is journaled on the concentric part of a sleeve or hub 4'32 mounted on the shaft 123, and having at its left end an eccentric portion 4133 on which is journaled a floating gear 484. Said floating gear has nine radial teeth, each one cut away on its left hand face, so that each tooth has a long part in the same plane as the teeth 481, with which it cooperates as shown in Fig. 18. This cooperation causes the floating gear to turn always through the same angle as the drive member notwithstanding the eccentricity of the floating gear and in whatever position the eccentric 4B3 may be. The foreshortened left hand portions of the teeth of the floating gear mesh internally with ten teeth 405 projecting rightward from the resultant wheel 406, so that said resultant wheel is geared to the floating gear and, therefore, to

the drive pinion H22, in the ratio of nine to ten. The teeth 405 are in the form of cylindrical studs. In the lowest or units order, the hub M32, 403, is fast to a disk MJSSU, like the disks of the resultant wheels, but having a single stud 401 projecting through an opening in the arm 524 (Fig. 19) so as to fix the hub against rotation. In each of the other orders, the eccentric is connected with the resultant wheel of next lower order by the sleeve 402 which constitutes the hub of said resultant wheel so that, in each order, the eccentric 403 rotates on the shaft I23 in unison with the resultant wheel of next lower order.

The slight respect in which the illustrated accumulator difiers from Gardners is that, in Gardner, a lug projecting from the periphery of each resultant wheel is used to arrest the wheel at zero, whereas, in the present instance, the disk is enlarged to a radius corresponding to that of said lug, and a notch 408, having one inclined and one abrupt surface, is cut in the disk to serve the same purpose as well as another purpose as will presently appear.

The clearing or zeroizing of the accumulator E20 is not effected by its actuating gears H as is common in computing machines, but is done by a separate set of'rack bars 259 (Fig. 1), one such bar for each order of the accumulator. These rack bars may also set indicating dials 25E, or printing types 252, or both, to indicate the result registered on the accumulator or to record it, as will presently appear. When the operating pinions I22 of the accumulator swing out of mesh with their actuators l Iii, they swing into mesh with their several racks 250. As the pinions are always in mesh with one or the other of these toothed members, they require no other detents. As shown, the rack bars 25E! are guided by frame bars or rods 253 passing through vertical slots in the bars, and spring clips 254% like the clips L33 already described. Each rack is drawn upward by a spring 255, and they are all restored to their normal bottom positions by a restoring bar 255 passing through a slot 259 in each bar. At each of its ends, the bar 255 is connected by a link '25! (Fig. 16) with a lever 258 of the first order, pivoted at 2653 and having a follower roller 26! riding on a cam 262 on the cam shaft M8. The restoring bar 25$ stands normally in its upper position, shown in Fig. 1, and, as will presently be described, the clearing bars 25%) are normally locked down, being released only to take a total. In multiplying operations, the restoring bar 255 may move down and up in the slots 259, but idly.

The indicator dials 25! are journaled on the shaft I25 and each has a pinion 265 constantly meshing with teeth of its associate rack 250. The dials normally show zeros, and when the racks rise under control of the accumulator wheels, these dials indicate the total.

The zeroizing mechanism comprises means cooperating with each rack 25!) whereby said rack is normally locked in its down position as shown in Fig. 1, and which, when a total key is depressed has the general mode of operation common with crawl carry accumulators, that is to say, the racks are released one at a time, beginning with the one of lowest order. Two transverse shafts 300 and 30! are arranged just behind the racks 2511. As shown in Fig. 5 and, enlarged, in Figs. 6 and 19, there are pivoted on the upper shaft 300 at each denomination, two levers, one, 3532 having a hub 393, and another 894 having a hub 3%. To avoid crowding, this system of levers is not let tered in detail in Fig. l, but is shown in Figs. 19, 20 and 21, where some of the parts are designated by their reference numerals with the addition of letters SU, U and T, signifying denominational orders, sub-units, units and tens, respectively. Each lever 302 and 35 5 has a rear arm drawn downward by a spring 391 and, at the proper time, restored upward by a restoring bar 368. The locking lever SE32 has an upper arm with a hook-like end normally engaging a stud 3H] on the side of the associate rack bar 259, and locking said bar down. A lower arm of said locking lever has an ear 35! formed off rightward from its end and engaging the end of a blocking member M2, pivoted on the lower shaft 39! and which positively retains said locking lever in looking po-- sition. The hub 36% has a, cut-out 313 (Fig. 6) to avoid interference with the rack 25!! of next higher order.

The lever 38% is herein called the tripping lever for brevity. It performs the dual functions of arresting its own accumulator wheel at zero and of tripping the blocking member M2 to release the levers 3G2 and SEM of next higher order to the action of their springs 3B1. Besides its horizontal arm above referred to, it has three arms M4, 355 and 386 (Fig. 21). The arm 3H6 is adapted, when released, to be pressed by the spring 381 against the cylindrical periphery of the resultant wheel of the accumulator and, as said wheel approaches zero, to slide down the incline of the notch lllB and finally to arrest the wheel. The arm 3 i 4 has a. lug or ear 3 i 8 formed off therefrom and normally resting on the end of the blocking member 3i2, which holds it'just out of contact with said resultant wheel. The arm 3i5 lies behind a stud are on the blocking member 3i2 which controls the levers 3M and 3% of next higher order, so that, when the arm 35 (i descends into the notch M8, the arm 3E5 will swing the blocking member 3 i2 counter-clockwise until the ears 3m and 3H drop off the end of it and free the next pair of levers 38 3 and 382. Two of these studs 320 are shown in Fig. 6. Thus each pair of locking and tripping levers, and with them their associate rack 25%, is released for operation at the instant when the accumulator wheel of next lower order reaches its zero position.

As indicated in Fig. 19, the car 368 of the tripping lever rests on the end of the blocking member 3E2 behind the ear 3H of the locking lever, so that, as the arm Bit of the next tripping lever to the right slides down the incline of the notch 08 in the accumulator wheel and the arm 3i 5 of said lever swings the blocking member counterclockwise, the ear 3E8 of tripping lever 33% will be released an instant prior to the release of the ear 3!! of the locking lever. This is so that, if the accumulator wheel associated with these two levers happens to stand already in its zero position, the arm 3| 6 of the tripping lever will have a moment of time in which to drop immediately into the notch 2-68 before the release of the locking lever permits the rack to start rising and turning the wheel. This swinging of the tripping lever will, of course, immediately trip the devices of the next succeeding denomination.

Comparing Figs. 19, 20 and 21 with Fig. 6 may clarify the mechanism. Fig. 21 shows the fixed sub-units disk 'GQGSU and the extra tripping lever SMSU, the-latter'cooperating with the stud 320U on the blocking member 3I 2U. Asshown in Fig. 6, this blocking member is behind the units-wheel, out of the plane of the lever SMSU", but the stud projects rightward into said plane. There is nothing holding this lever in its normal inactive position, except the restoring bar 308. The arms 3 l 4 andv 3 it are functionless in this one lever, and may be out oif if desired. Fig. 20 shows the looking lever 302U, cooperating with the stud 31 011 of the units rack. The upper part of said rack is broken away and the stud 3LOU is shown in section. The ear 3I-IU is standing over the end of the blocking lever 3i2U and will be held up by it when the restoring bar 308 drops down. In Fig. 19 these same parts are shown in the same way, and, behind the lever 3021i is shown the tripping lever 3'04U, with its car 3 8U" standing above the blocking lever 31211. The relations of the parts will be apparent in Fig. 6.

The restoring bar 308 is a-bail bar mounted on two arms 325 (Figs. 1 and 5) whose hubs are fast on the shaft 300. The right hand one of said arms is connected by a push link 326 with a,- lever 32! pivoted on the shaft 243 and carrying a follower roller 328 (Fig. 13) adapted to be moved downward by a cam 330 on the cam shaft M0. The rock shaft 300 has fast thereon an arm 334 (Fig. l) normally engaged by a latch 33! comprising one arm of a total key lever having a total button or key 333 on its front end. Said total key lever is pivoted on a stud 33d and urged to locking position by a spring 335.

The operation is as follows: When the parts are in their normal positions, the restoring bar 303 is up, holding all of the tripping and locking levers 304 and 302 out of action and it is locked in that position by the latch 3'32; and thecam- 330 has its high part out of the path of movement of the roller 32-8. With the mechanism in this condition and the cam shaft M standing still in its normal position, a depression of the total key will result in the restoring bar dropping down (clockwise) and the follower roller 328' moving up into the orbit of the cam 330. When the bar 308 drops, all of the locking levers 302 are retained by the blocking members 3l2, and so: are all of the tripping levers 304- eXcept the sub-units lever SiidSU. The latter immediately swings clockwise and acting on the stud 32-313, rocks the units blocking member 3 l2U counter-clockwise, releasing the units tripping and locking levers 304U and 30211, thus permitting the units rack to rise, turning the units resultant wheel to zero, if a number stands registered thereon. The tripping lever EMU rests on the periphery of the resultant wheel until the latter approaches zero, when it slides down into the notch 408 which arrests the wheel. The rocking of this lever trips the blocking member 3W1, and initiates the zeroizing of the tens wheel; and so on across the series of orders.

It will be noted in Figs. 5 and 19 that the ear 3 l 8 of the tripping lever 304, rests on the blocking member 3l2 behind the ear 3H of the locking lever, so that, when the latter is rocked the tripping lever is released an instant sooner than the locking lever. This is so that, if the resultant wheel is already standing at zero, the arm (Hi3 of the tripping lever will fall immediately into the notch 408'before the locking lever has time to release the rack and start it to-rotating thewheel. At the end of thezeroizing operation, the several racks 250 will have risen each as far as permitted by its associated tripping and arresting (ill lever 30.4, the dials 25! will have: been rotated correspondingly to indicate the total: visually and the types 252 to print the total will have been aligned before the. platen.

The operating mechanism is so. contrived that an, operationof multiplying a multiplicandxset up on the keys I50 by a multiplier digit set up by a key l5l, will be executed. by one rotation of the cam shaft I40 in either direction from its normal position; and such that when the shaft is turned (by its crank) counter-clockwise, the product is entered in the accumulator I20 additively, where.- as, when said shaft is turned clockwise, the product will be entered subtractively.

In the timing diagram, Fig; 12, the degrees of rotationare designated at the top of the diagram from left to right, for a clockwise rotation, and at the bottom of the diagram from right to left for a counter-clockwise rotation. Comparingthe first two lines of the diagram beginning at their right ends, it will be seen that on a counterclockwise rotation, the accumulator remains in its normal position out of mesh with its actuators I [6 from 0 to and that meanwhile, from 10 to 130, the restoring bar I31, and with it the rack bars [30 and the multiplying trains, have effected their advance movement to where the racks hill and 142 have been arrested by their respective key stops I60 and 205. From 130 to the restoring bar l3! dwells in its advanced position and the accumulator moves into mesh. From 180 to 300, the accumulator remains in mesh while the restoring bar i3! restores the multiplying trains thus adding the product on the accumulator, which then moves out of mesh, 300 to 350.

When the crank. is turned clockwise, the diagram, read by its upper degree designation, shows the accumulator first moves into mesh, 10 to 60, and the restoring bar advances from. 60 to 180, subtracting the product as the racks advance against their stops. The restoring bar dwells in itsadvanced position while the accumulator moves out of mesh from. 180 to 230, and the multiplying trains are then restored, 230 to 350.

Acomplete multiplication. of a multiplicand by a plural digit multiplier may beefiected by setting the multiplicand key-board in its. extreme right hand position, setting up the multiplicand on. the keys 150, depressing the key of the units digit of the multiplier, and giving the crank one counterclockwise rotation; then moving the keyboard one space to the left, depressing the multiplier key of the tens digit and againrotating the crank; and so on.

Itwill be-understood, of course, that a number may be added on the accumulator by setting it up on the multiplica-nd key-board and multiply ing it, by one. A number of eight digits may be added in two operations, adding the four highest places with the key boardinits extreme. leit hand positions and, the. four lowest digits with saidkeyboard in its extreme right. hand position.

To take a total, the total key 3331 is depressed While the cam shaft M0 is at rest in its normal position. This frees the shaft 300 and restoring bail 308 from restraint by the hook or latch 332, and allows the rack bars 250 to rise, each until arrested when its associate accumulator wheel reaches zero, all as hereinbefore described. After transcribing the total from the dials 25 i, or printing it by the types 252, the parts may be restored to normal by a counter-clockwise rotation of the 35 cam shaft Mil. As shown on the last three lines of the time chart (Fig. 12) from 10 to 60, the accumulator moves out of mesh with the total racks 250 and into mesh with the actuators H6, where they remain until 180. The racks 253 are restored during this interval, 60 to 180, the restoring bar 256 then resting in its advanced (lowermost) position until 230. At from 180 to 230, the cam 33f! raises the pawl-restoring bail 3B8, rocking the shaft 390 counter-clockwise until it is locked in that position by the latch 332, thus locking down all of the racks 25E in the manner hereinbefore described. At from 250 to 300, the high part of the cam 33 moves away from the 'follower 328, leaving the bail 398 free to drop again when the total key is again depressed. From 230 to 310, the restoring bar 25% moves to its normal upper position, leaving the racks 25%] free to rise when the total key is depressed.

Various changes, besides those hereinbefore mentioned, may be made in the details of construction and arrangement, without departing from the invention.

What I claim as new, and desire to secure by Letters Patent is:

l. The combination of a pair of logarithmic gears consisting of a logarithm member and a numeral member interconnected by spirally disposed gear teeth over a range of movement from a position wherein the numeral member stands at one and the logarithm member stands at zero to a position in which the numeral. member stands at n and the logarithm member stands at log n, and an additional coupling between the two members effective to permit a supplemental movement of the numeral member from its one position to its zero position; and an accumulator wheel geared to and operated by said numeral member.

2. In a multiplying train, the combination of a logarithm member one portion of which is a logarithmic spiral gear and another portion of which is a spur gear, and a cooperating numeral member one portion of which is a spiral gear cooperating with the said logarithmic spiral and another portion of which is a spur gear cooperating with the first said spur gear, said spiral gears meshing through a range of 81 to 1 on said numeral gear and said spur gears meshing through a range of 1 to on said numeral gear.

3. In a multiplying train, the combination of a logarithm member one portion of which is a logarithmic spiral gear and another portion of which is a spur gear, a cooperating numeral member one portion of which is a spiral gear cooperating with the said logarithm spiral and another portion of which is a spur gear cooperating with the first said spur gear, said logarithm and numeral members normally standing with said spur gears in mesh; means to impart to said numeral member a movement from zero to one and to said logarithm member an empirical movement to zero while said spur gears are in mesh, and, while said spiral gears are in mesh, to impart to said numeral gear movements from 1 to 81 and to said logarithm gear movements through distances appropriate to the logarithms of 1 to 81, and means to limit the movement of said logarithm gear in accordance with the sum of the logarithms of two factors plus said empirical movement.

4. In a machine for multiplying numbers, the combination of an actuating rack, a multiplicand rack, a multiplier rack, differential gearing connecting said multiplicand and multiplier racks with said actuating rack, a logarithmic spiral pair actuated by said actuator rack including a numeral spiral and a logarithm spiral, means to determine advance movements of said multiplicand rack to positions appropriate to the logarithms of multiplicand digits, means to control advance movements of said multiplier rack to positions appropriate to the logarithms of multiplier digits, and means to restore said actuating rack to a normal position beyond its log 1 position to bring said numeral spiral to zero position.

5. In a computing machine the combination of a spiral pair comprising a logarithm spiral rotatable from initial position through angles 3/ appropriate to the logarithms of numbers a: rang- I ing from one to eighty one and a numeral spiral rotatable uniform distances according to said numbers a: from position one to position eighty one, all according to the formula y=a.log ac and differential mechanism comprising a member to operate said logarithm spiral, a member operable through distances proportional to the logarithms of multiplicand digits, a member operable through distances proportional to multiplier digits, and a differential gear connecting the three said members to control the movements of said operating member in accordance with the sum of the movements of the other two said members.

6. The combination with a logarithmic pair comprising a logarithm spiral and a numeral spiral, of a main rack geared to said logarithm spiral, a multiplicand rack and a multiplier rack connected with one another and with said main rack by a differential gear, means settable to determine a movement of said multiplicand rack, means settable to determine a movement of said multiplier rack, means to lock said main rack in normal position, and means controlled by the combined action of the two said settable means to release said locking means.

7. In a computing machine, the combination of a logarithmic spiral pair comprising a logarithm spiral and a numeral spiral, a rack geared to operate said logarithm spiral, a multiplicand rack, a multiplier rack, a differential gear connecting said multiplicand and multiplier racks with said operating rack, in-put means settable to control movements of said multiplicand rack in proportion to the logarithms of multiplicand digits, input means settable to control movements of said multiplier rack in proportion to the logarithms of multiplier digits, and locking means for said operating rack released by the setting of both said in-put means.

8. In a calculating machine, the combination of a series of denominational logarithmic multiplying trains each comprising a logarithm member and a numeral member, a rack to operate said logarithm member, a multiplicand rack, means to hold said operating rack in a zero position where said rack is retracted beyond its initial logarithmic position, multiplicand digit stops, means to set said stops selectively and, concomitantly, to release said holding means, a multiplier rack, difierential gearing connecting said multiplier and said multiplicand racks jointly to control said operating rack, multiplier stops common to a succession of said multiplier racks, a common means to restrain all of a succession of said operating racks in their said zero positions, and means to set said multiplier stops se- 17 lectively and concomitantly to release said common restraining means.

9. In a machine for multiplying numbers, the combination of a series of denominational logarithmic gear pairs each including a logarithm spiral and a numeral spiral intermeshing over a range of movement from 1 to 81, an accumulator having denominational wheels, and gearing connecting each said numeral spiral with the appropriate accumulator wheel to convey to said accumulator wheels the movements of said numeral spirals, and means to add 1 at each actuation of a logarithmic pair.

10. In a computing machine, the combination of a series of denominational logarithmic gear pairs each including a logarithm spiral and a numeral spiral intermeshing over a range of movement from 1 to 81, means including a differential mechanism to set each said logarithm spiral in proportion to the sum of two logarithms in one stroke, an accumulator having denominational wheels, and gearing connecting each of the said numeral spirals with the appropriate accumulator wheel to convey to said accumulator wheels the movements of said numeral spirals, and means to add 1 at each actuation of a logarithmic pair.

HAROLD P. MIXER.

REFERENCES CITED The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 179,737 Smith July 11, 1876 1,028,135 Rein June 4, 1912 10 1,221,027 Cluley Apr. 3, 1917 1,332,543 Cluley Mar. 2, 1920 1,482,153 Ross Jan. 29, 1924 1,503,810 Ross Aug. 5, 1924 1,867,002 Gardner July 12, 1932 15 1,889,876 Pellerin et a1 Dec. 6, 1932 2,261,341 Crosman Nov. 4, 1941 2,342,529 Chase Feb. 22, 1944 FOREIGN PATENTS Number Country Date 334,733 Italy Jan. 29, 1936 340,013 Great Britain Dec. 12, 1930 445,787 Great Britain Apr. 20, 1936 

